Sorry, I do not think there is a direct answer to that.....
In my opinion SAL are paceful fishes, unles they are disturbed, pro example if the RD do not allow him to eat.
Then the SAL will take revenge when the lights are turned off....
I use to have a 26 in. SAL with two full grown oscars in a very well filtered 50gal. So technically It is possible. But Red Devils are defferent (very very aggresive) .....
But keep in mind that feeding the SAL With the Devil in the same tank will be somewhat laborious. The SAL is very slow...
That is a good little one. When he grows he will turn dark gray and ll loose the yellow freckles.
But will be still an amazing fish. Mine is 4/5 years old and 27" long. I have him with two big Oscars and several little cichlids.